1. Technical Field of the Invention
This invention relates to the preparation of predominantly linear polyethylenepolyamines from ethylenediamine and monoethanolamine in the presence of unique activated carbon catalyst compositions.
2. Prior Art
Heretofore, polyethylenepolyamine compounds such as diethylenetriamine, triethylenetetramine and the higher homologs have been produced by the reaction of an alkyl halide such as ethylene dichloride with an amine such as ammonia or ethylenediamine at elevated temperatures and pressures. Normally, relatively high yields of predominantly non-cyclic polyethylenepolyamine compounds are obtained from this process with varying yields of heterocyclic amines. The large amounts of energy required to produce the reactants as well as the difficult separation procedures required to recover the more valuable linear polyethylenepolyamines diminishes the usefulness of the ethylene dichloride process. The hydrohalide salts of ammonia and the polyethylenepolyamine products must also undergo difficult and time consuming caustic neutralization to yield the free polyethylenepolyamines.
It has heretofore been known that phosphates can be used to catalyze amine reactions to produce predominantely heterocyclic rather than linear products. Thus, U.S. Pat. No. 3,297,701 teaches the use of aluminum phosphate to catalyze the reaction of ethanolamines and polyethylenepolyamines to yield cyclic compounds. U.S. Pat. No. 3,342,820 discloses the use of aluminum phosphate for the preparation of heterocyclic compounds such as triethylenediamine. As another example, U.S. Pat. No. 4,103,087 also discloses the use of aluminum phosphate catalysts for producing heterocyclic product compounds.
More recently, investigators have found that more linear products can also be obtained in a catalytic conversion. Thus, Ford et. al. U.S. Pat. No. 4,316,840 discloses the preparation of polyalkylenepolyamines from ethylene diamine utilizing a metal nitrate or sulfate as a catalyst. U.S. Pat. No. 4,314,083 discloses the reaction of ethylene diamine with monoethanolamine to prepare noncyclic polyalkylenepolyamines using, as a catalyst, a salt of a nitrogen or sulfur-containing compound.
In inventions more recently made in our laboratories, Brennan et. al. in U.S. Pat. No. 4,036,881 discloses the use of phosphorous-containing catalysts to catalyze the reaction of ethylenediamine with monoethanolamine. Excellent results were obtained when the reaction was conducted in an autoclave. However, when the phosphorous compound was supported on silica or diatomaceous earth, good results were obtained only at comparatively low conversions. Brennan et. al. U.S. Pat. No. 4,044,053 is also relevant in this regard. Brennan U.S. Pat. No. 4,103,087 discloses the use of pelleted aluminum phosphate to prepare di-(N-N-disubstituted amino)alkanes. Good results have been obtained using a catalyst of this nature in batch-type reactions.
Activated carbon is generally characterized as a chemically inert material, prepared in a manner to provide good porosity and a higher surface area. It is widely used in the chemical area for the removal of unwanted impurities from chemical products. It has been used successfully for this purpose in the purification of amines by flowing a stream of an impure amine through a bed of activated carbon to improve color or other physical or chemical properties of the amine.
A group of recently filed U.S. patent applications in which I have participated disclose inventions directed to the reaction of ethylenediamine with monoethanolamine in the presence of catalysts comprising a compound of phosphorous supported on a Group IVb metal oxide (Vanderpool U.S. patent application Ser. No. 455,160 filed Jan. 3, 1983 and entitled "Catalysts and Preparation of Linear Polyethylenepolyamines Therewith"), such as: calcined pellets of titania having phosphorous deposited thereon (Vanderpool et. al. U.S. patent application Ser. No. 455,158 filed Jan. 3, 1983 entitled "Calcined Catalyst and Preparation of Linear Polyethylenepolyamines Therewith"); titania having phosphorous derived from polyphosphoric acid deposited thereon (Larkin et. al. U.S. patent application Ser. No. 455,159 filed Jan. 3, 1983, entitled "Linear Polyethylenepolyamine Preparation and Catalyst"); group IVb metal oxide pellets having phosphorous derived from phosphoryl chloride or phosphorous bromide deposited thereon (Vanderpool et. al. U.S. patent application Ser. No. 455,156 filed Jan. 3, 1983, entitled "Modified Catalysts and Preparation of Linear Polyethylenepolyamines Therewith"); titania pellets having phosphorous derived from a trialkyl phosphate or trialkyl phosphite deposited thereon (Watts et. al. U.S. patent application Ser. No. 455,155 filed Jan. 3, 1983, entitled "Preparation of Linear Polyethylenepolyamines from Novel Catalysts"); or pelleted titania having phosphorous derived from a diamminohydrogen phosphate deposited thereon (Renken U.S. patent application Ser. No. 455,153 filed Jan. 3, 1983, entitled "Supported Phosphate Catalysts and Preparation of Linear Polyethylenepolyamines Therewith",). Also included in this group of filings is Vanderpool U.S. patent application Ser. No. 455,154 filed Jan. 3, 1983, entitled "Catalytic Preparation of Linear Polyethylenepolyamines with Supported Catalyst") which discloses the use of zirconium silicate pellets having phosphorous deposited thereon and Vanderpool et. al. U.S. patent application Ser. No. 455,346 entitled "The Preparation of Linear Polyethylenepolyamines with Supported Catalysts" which discloses the use of alumina and/or aluminum phosphate having phosphorous derived from phosphoryl chloride deposited thereon. Also, Brennan U.S. patent application Ser. No. 453,841 entitled "Preparation of Linear Polyethylenepolyamines with an Aluminum Phosphate Catalyst" is directed to the use of a catalyst prepared by reacting alumina with phosphoric acid and that reaction product with ammonium hydroxide.
Zall U.S. Pat. No. 3,876,451 discloses a sewage treating process wherein activated carbon containing cations such as aluminum, manganese, zinc, iron, lithium or calcium is used to sequester phosphates in the waste effluent that would otherwise be discharged into environmental waters.